2-Carbomethoxy-aminobenzimidazoles

ABSTRACT

Benzimidazole derivatives of the formula   wherein R1 is alkyl or cycloalkyl and R2 is alkyl, haloalkyl, cycloalkyl or optionally substituted phenyl, benzyl or naphthyl, are valuable fungicides and anthelmintics.

' United States Patent [191 Horlein et a].

[4 1 Nov. 4, 1975 Z-CARBOMETHOXY- AMINOBENZIMIDAZOLES [75] Inventors: Gerhard Hiirlein, Frankfurt am Main; Hilmar Mildenberger, Kelkheim am Taunus; Arno Kriiniger, Hotheim am Taunus; Kurt Hiirtel, Hofheim am Taunus; Dieter Diiwel, Hofheim am Taunus; Reinhard Kirsch, Hofheim am Taunus, all of Germany [73] Assignee: Hoechst Aktiengesellschaft,

Frankfurt am Main, Germany 22 Filed: Nov. 20, 1973 21 Appl. No.: 417,640

[30] Foreign Application Priority Data Moore 260/3092 Brake 106/15 AF Primary ExaminerG. Thomas Todd Attorney, Agent, or FirmCurtis, Morris & Safford [57] ABSTRACT Benzimidazole derivatives of the formula wherein R is alkyl or cycloalkyl and R is alkyl, haloalkyl, cycloalkyl or optionally substituted phenyl, benzyl or naphthyl, are valuable fungicides and anthelmintics.

8 Claims, No Drawings 2-CARBOMETHOXY-AMINOBENZIMIDAZOLES The present invention provides benzimidazole compounds of the formula I where R is alkyl having from one to 12 carbon atoms or cycloalkyl having from four to eight carbon atoms and R is alkyl having from one to 12 carbon atoms, halo-alkyl having from one to 20 carbon atoms, cycloalkyl having from five to eight carbon atoms, phenyl, benzyl or naphthyl, the last three optionally being substituted by halogen, alkyl having from one to four carbon atoms or alkoxy having from one to four carbon atoms, cyano and/or nitro.

Preferred radicals R are alkyl having from one to six, especially from one to four carbon atoms, or cycloalkyl having from four to six carbon atoms, especially cyclohexyl.

Preferred radicals R are alkyl having from one to 12 carbon atoms, cyclohexyl, methylphenyl, chlorophenyl, fluorophenyl or nitrophenyl.

The present invention provides also a process for the preparation of benzimidazoles of formula I, which comprises reacting 2-carbomethoxy-aminobenzimidazole of the formula II with a sulfonyl-isocyanate of the formula III OCN-SO -IIlSO R- (III) according to known methods.

A preferred embodiment of the process of the invention is the following: the 2-carbomethoxy-aminobenzimidazole (II) is suspended or dissolved in a solvent and the isocyanate is added with agitation. The reaction is generally slightly exotherrnal. Heating for some time in order to complete the reaction is also possible. The temperatures are preferably from to 80C, especially from to 40C, but the temperature range is not critical. The reaction product is generally obtained in a crystallized form and may be isolated by filtration.

The reaction products are characterized by elementary analysis, decomposition points and IR spectra.

Suitable solvents for the reaction are for example solvents of mean or weak polarity, especially those having low boiling points and which do not react with isocyanates, for example methylene chloride, chloroform, carbon tetrachloride, benzene; ethers such as diethyl ether, diisopropyl ether or tetrahydrofuran; esters such as methyl acetate and ethyl acetate; or ketones such as acetone or methylethylketone. Preferably, chloroform or methylene chloride are used.

The Z-carbomethoxy-aminobenzimidazole may be prepared according to the method described in J. Amer. Soc. 56, 144 (1934) by reaction of ophenylenediamine with S-methyl-isothiourea-dicarboxylic acid-dimethyl ester.

The compounds of formula III may be prepared by reacting sulfonamides of the formula IV with chlorosulfonyl-isocyanate at temperatures of from to 200C, preferably from to C.

The compounds of the invention have a good fungicidal, especially systemic, action and so are particularly useful for combating fungi which have entered plant tissues. This is especially important in the case of those fungus diseases which have a. long incubation period and, after the outbreak of the infection, cannot be combated by the usual fungicides. The activity range of compounds of the invention is very broad and they are effective against a number of fungi important in crop farming, fruit growing, viti-culture, hop growing, and horticulture, for example, genuine mildew fungi (Erysiphaceae), Rhizoctonia spp., Scerotinia spp., Botrytis spp., rust fungi, Fusarium spp., Cercospora spp., Septoria spp., Microsphaerella spp., Fusicladium spp., Venturia spp., Cladosporium spp., Colletotrichum spp., Verticillium spp., Glocosporium spp., Cylindrosporium spp., Cercospora spp., Cercosporella spp., Ustilago spp., Penicillinum spp.

The compounds of the invention are also useful for protecting stored fruits or vegetables against fungus infection, for example, by species of Fusarium or Penicillium. Furthermore, they are suitable for protecting textiles, wood, dyes, coatings or paints against fungal infestation.

The present invention therefore provides pesticide, especially fungicides comprising benzimidazoles of formula (I) as active substance, especially in concentrations of from 0.5 to 80 in admixture or conjunction with one or more known formulation additives, for example, solid or liquid inert carriers, adhesives, wetting and dispersing agents and grinding auxiliaries, in the form of wettable powders, emulsions, suspensions, dusting powders or granules. The compounds of formula I may be mixed with other fungicides with which they form compatible mixtures.

As carrier material, mineral substances, for example, aliminium silicates, argillaceous earths, kaolin, chalks, siliceous chalks, talcum, kieselguhr or hydrated silicic acids can be used, or preparations of these mineral substances with special additives, for example, chalk with sodium stearate. As carrier material for liquid preparations, any suitable organic solvents may be employed, for example, toluene, xylene, dioxan, dimethyl formamide, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, chlorobenzene, and other similar substances.

Suitable adhesives are glue-like cellulose products or polyvinyl alcohols.

As wetting agents, any suitable emulsifiers may be used, for example, ethoxylated alkylphenols, salts of arylor alkyl-aryl-sulfonic acids, salts of oleyl-methyltaurine or of ethoxylated benzene-sulfonic acids, or

p I A. EXAMPLES OF PREPARATION Suitable dispersing agents are cellulose pitch (salts of EXAMPLE 1 ligninsulfonic acid), salts of naphthalenesulfonic acid 177 g 1092 mole) f g i b or Salts of oleyl-methyl-taurine. v 5 zimidazole and 20 g 0.093 mole) of N-methyl- As grinding auxiliaries, suitable inorganic or organic methanesulfonamido-N-sulfonylisocyanate were salts, for example sodium sulfate, ammonium sulfate, stirred in 200 ml of chloroform for minutes at about sodium carbonate and sodium bicarbonate, sodium C. Subsequently, the reaction product was isolated thiosulfate, sodium stearate, or sodium acetate may be by suction-filtration. Yield: g. Melting point: 170C used. 10 (decomp.)

calc. N 17.3 S 15.8

O=CNH-SO2-N-SO2CH3 found N 17.4 s 15.5

The products of the process of the invention are fur- EXAMPLE 2 therrnore valuable anthelmintics and can be used espe- 13.7 g (0.071 mole) of 2-carbomethoxy-aminobencially for combating nematodes and their different (16- 25 zimidazole were suspendedin 200 ml of methylethylkevelopment stages parasitizing in the alimentary tract of tone, and 20 g (0.0725 mole) of N-methyl-benzenesulman and animal. The products are administered orally fonamido-N-sulfonylisocyanate were added. After 2 or subcutaneously, the application concentration being hours of refluxing, the reaction product was filtered off. in a range of from 0.5 to 5 mg/kg of body weight (s.c.) Yield: 29.5 g. M.p.: 142C (decomp) CH3 found: N 14.8 S 13.9

or from 2.5 to 50 mg/kg of body weight (p.o.). For an EXAMPLE 3 oral administration, solid application forms such as tabg (0.2 mole) of 2-carbomethoxy-aminobenlets, dragees, powders or granules are preferred, for a zimidazole were introduced into 200 ml of chloroform, subcutaneous administration, liquid preparations such and 74 g (0.21 mole) of N-butyl-(p-chloro)-pheny1sulas emulsions, suspensions or solutions are used. For the fonamido-N-sulfonylisocyanate were added dropwise. formulation of such preparations, usual, physiologically After 20 hours of agitation at 20C, the solution was acceptable auxiliaries and carriers are suitable, for exconcentrated, 100 ml of ether were added, and the rear nple talc, lactose, magnesium stearate (solids), or waaction product was filtered off. Yield: 95 g. M.p.: 75C ter, paraffin oil or polyols such as polyethyleneglycol. (decomp) j -(:1 calc.:N 12.9%; 511.8%

found N 13.3 7c; S 11.4

The activity of the compounds of the invention EXAMPLE 4 against Nematospiroides dubius, Ankylostomae in man In the manner as described in Example 3, g of reand domestic animals, Haemonchus spp.," Ostertagia action product were isolated from a batch of 46 g (0.24 spp., Trichostrongylus in ruminants, Hyo'strongylus inmole) of 2-carbomethoxy-aminobenzimidazole and 84 pigs and other animals is especially pronounced. 65 g (0.24 mole) of N-propyl-(p-nitro)-phenylsul- The following examples illustrate the invention. fonamido-N-sulfonyl-isocyanate. Melting point 156C.

EXAMPLE 5 39.2 g (0.206 mole) of 2-carbomethoxy-aminoben- 1 zimidazole and 80 g (0.206 mole) of N-cyclohexyl-(pnitro)-phenylsulfonamido-N-sulfonyl-isocyanate were refluxed with agitation in 300 ml of methylene chloride for 5 hours. Non-reacted starting compound was suc- -tion-fi1tered, the filtrate was concentrated, and 200 ml of ether/petrol ether (1 2) were added. The reaction product was obtained in the form of a colorless powder.

Yield: 64 g. M.p. 85 87C.

EXAMPLE 6 In a manner as described in Example 1, 42 g of reaction product were obtained from 28.6 g (0.15 mole) of 55 2-carbomethoxy-aminobenzimidazole and 64.6 (0.2 mole) of N-ethyl-(p-chloro )-pheny1sulfonamido-N-sul- C 19 ZO 6 9 2 calc. N 15.5

calc. N 14.5

found: N 15.8%; S 11.3%

fonyl-isocyanate in 200 ml of tetrahydrofuran. Melting 0 point: 159 162C.

EXAMPLE 7 28.6 g (0.15 mole) of 2-carbomethoxy-aminobenzimidazole and 62 g (0.2 mole) of N-methyl-(p- 25 chloro)-phenyl-sulfonamido-N-sulfonyl-isocyanate in 200 ml of chloroform were stirred for hours at about C. The reaction product was isolated by filtration. Yield: 60 g. M.p.: 157 159C (decomp.)

found N 15.1 S 11.0%

-NH-COOCH; C H ClN O S MW 569.5

c.a1c.:N 12.3 S 11.2

found N 12.5 S 11.5

EXAMPLE 9 28.6 g (0.15 mole) of 2-carbomethoxy-aminobenzimidazole were suspended in 300 ml of anhydrous acetic acid ethyl ester, and 66.4 g (0.2 mole) of N- butyl-p-tolyl-sulfonamido-N-sulfonylisocyanate added at 20C. The mixture was stirred for about 10 hours at 35C, filtered off the portion of non-reacted starting product, and concentrated. After addition of 200 ml of ether to the residue, 52 g of reaction product having a melting point of 125 128C (decomp.) were obtained.

were 5 (decomp.)

c n w ms MW 523 O=CNH-SO2NSO2 c11 calc. N 13.3 s 12.2

C4119 found N 13.3 s 12.7

EXAMPLE l0 EXAMPLE 12 28.6 g (0.15 mole) of 2-carbomethoxy-aminoben- 40 zimidazole and 46 g (0.2 mole) of N-methyl-ethylsulfonamido-N-sulfonylisocyanate were stirred in 400 ml of chloroform for about 9 hours at 25C. The reaction product was isolated by filtration. Yield: 53 g:' M.p.: 141 144C N\ NH-COOCH N I a 45 fonylisocyanate in 400 ml of methylene chloride.

c1-1 found N 16.3%; s 15.7

C 11 found N 16.2 S 13.8

In analogy to Examp be obtained:

le l 2, the following substances can -continued B. EXAMPLES OF APPLICATION In the following examples of application, the following known compounds were used in their commercial form as comparative agents:

Compound 1 Maneb (manganese-ethylene-bis-dithiocarbonate) II N NHCOOCH DOS* 1 956 157 III Zinob (zinc-ethylene-bis-dithiocarbamate) IV Dinocap (2-[ l-methylheptyl]-4,6-dinitrophenyl-c rotohate) V Benomyl (2-carbomethoxyamino-l-n-butylcarbamoylbenzimidazole) I DOS* 1 956 VI BCM (2-carbomethoxyamino-benzimidazole) DOS* 1 620 DOS German Ofi'enlegungsschrift EXAMPLE I Sugar beet plants grown in pots in the 6-leaf stage were heavily infested with conidia of the beet leaf spot organism (C ercospora beticola) and placed in a moisture chamber at 25 "C and a 100 relative atmospheric humidity, where they were kept for one day. Subsequently, they were placed in a greenhouse having a relative atmospheric humidity of ofrm 80 to 90 and a temperature of from 25C. After an infection time of 10 days, the plantswere sprayed, until drip-off, with the compounds cited in Examples 1 and 2. The application concentrations were 120, 60, 30, and mg/l of spray liquor. As comparative agents, the compounds I and II were used in the same application concentrations. After drying of the spray liquor, the plants were placed again in the greenhouse. After an incubation period of 3 weeks, the plants were examined for infection with beet leaf spot. The evaluation was carried out visually, and the degree of infection expressed in of infested leaf area, as compared to untreated, infested control plants 100). The results are shown in Table I.

Tomato plants, in the stage of completely grown 3 having a high relative atmospheric humidity and an optimum temperature for infection of 25C. After incubation period of 10 days, the plants were treated with the compounds according to Examples 1 and 2 in concentrations of 120, 60, and 30 mg/] of spray liquor until drip-off. As comparative agent, the compound II and III were used in the same concentrations.

After drying of the sprayed layer, the plants were again placed in the greenhouse and, after an incubation period of 3 weeks, examined for infection with leaf mould. The infection was examined visually, as usual, and the degree of infection was expressed in of infested leaf area relative to untreated, infested control plants 100). The results are shown in Table II,

Cucumber plants in the two-leaf stage were heavily infested with conidia of the cucumber mildew (Erysiphe cichoracearum) and placed for 24 hours in a moisture chamber having a relative atmospheric humidity of 100 and a temperature of 20C. Subsequently, they were placed in a greenhouse having optimum infection conditions such as a high relative atmospheric'humidity (8O and a temperature of from 20 to 22C. After days, the plants were treated until drip-off with the compounds according to Examples 1 and 2 in concentrations of 120, 60, 30 and mg of active substance per liter of spray liquor.

As comparative agents, the compounds II and IV were used in the same concentrations of active substance.

After drying of the sprayed layer,-the plants were again placed in the greenhouse, where they were kept until the outbreak of the disease 14 days after infection. Examination was carried out visually, as usual. The degree of infection was expressed in of infested leaf area, relative to untreated control plants 100), as shown in Table III.

Apple seedlings in the 6-leaf stage were infested with conidia of the apple mildew (Podosphaera leucotricha) and placed in a greenhouse having a relative atmospheric humidity of from 80 to 90C and a temperature of C. After an infection time of 5 days, the plants were treated, until drip-off, with the compounds according to Examples 1 and 2 in concentrations of 60, 30, 15 and 7.5 mg/liter of spray liquor.

As comparative agents, the compounds II and IV were used in the same concentrations of active substance.

After drying of the sprayed layer, the plants were again placed in the greenhouse and, after an incubation period of 3 weeks, examined visually for infection with the apple mildew. The results are expressed in of infested leaf area, relative to untreated, infested control plants 100).

Winter wheat in the four-leaf stage was treated until drip-off with the following compounds: Examples 7, 6, 3, 9, 8, 5, 4, 10, 1 l and 12. The application concentrations were of 120 and 60 mg of active substance per liter of spray liquor.

As comparative agents, the compounds V and VI were used in the same application concentrations. The test was carried out with a four times repetition.

After drying of the sprayed layer, the plants were heavily infested with conidia of the powdery mildew of cereals (Erysiphe graminis) and subsequently placed in a greenhouse having a temperature of from 20 to 22C and a relative atmospheric humidity of from to After an incubation period of 14 days, the plants were visually examined for infection with mildew and the results expressed in of infested leaf area, relative to untreated, infested control plants (see Table V).

The results of Table V show that the compounds of the invention, when the same molar amounts are used, have the same activity as comparative agent V, but are considerably more efficient than comparative agent VI.

EXAMPLE VI Sugar beet plants in the 6-leaf stage were heavily infested with conidia of the beet leaf spot (Cercospora beticola) and placed dripping wet into a moisture chamber having a temperature of 25C and a relative atmospheric humidity of After a residence time of 2 days in this chamber, the plants were transferred to a greenhouse having a temperature of from 25 to 26C and a relative atmospheric humidity of from 85 to 90 After an infection time of 6 days, the plants were treated with the compounds cited in Example I and the comparative agents indicated there with a four times repetition. The application concentrations were 250, and 60 ml of active substance/liter of spray liquor.

After drying of the sprayed layer, the plants were placed again in the greenhouse and, after an incubation time of 24 days, examined for infection with the beet leaf spot. The degree of infection was expressed in of infested leaf area, relative to untreated, infested control plants.

As the results of Table VI show, the compounds of the invention have an excellent activity equivalent to comparative agent V and superior to comparative agent VI.

TABLE V of mildew infection at mg Compound of Example infection with Cercospom at mg of substance/liter of spray liquor 250 125 60 12 0 O 18 Comparative agent V 0 0 8 Comparative agent VI 5 15 3O TABLE VI-continued 1 TABLEVIIIJ Compound of Example infection with Cercospora at Preparation I l .l T L Dose mg of substance/liter of spray Example i f Parasite l King/ g) I PP li uor I 250 6o 5 4 "Ankylostom'ae "LX 20 p.o. 98 6 Ankylostomae -l- '2O p.o. -O untreated plants 100 100 100 10 Ankyloswmae 1 X P- 85 9 I Ankylostomae 1 X 20 p.o. 100 methyridin* Ankylostomae 1' X 200 s.c.*** O thiabendazolt" Ankylostomae l, 500 p.o.' 82

EXAMPL VII 10 McGregor, 1.x;v uu. Lord a. A.A. Kingscote, Canadian Vet/J. 3, 67 68, 1962 A test of anthelmintic activity was carried out as follows:

In order to cause artificial infection, 100 actively mobile larvae of Nematospiroides dubius in 0.3 ml of water were administered orally to about 4 weeks old mice. The animals so infected were kept in cages each containing two animals, and they were fed with standardized food and water ad libitum. After termination of the prepatency period, the animals were treated with the compound to be tested 1 to 3 consecutive days. 3 to 5 days after the last treatment, the animals were killed, the intestines were taken off and the worms were counted. The efficiency is expressed in percent of worm load of animals treated as compared with the worm infection of untreated control animals (controlled test). By a good anthelmintic effect there is to be understood the reduction of the worm load by more than 95 In the following Table VII, a selection of compounds of the process of this invention and comparative products are listed.

*tolerance limit EXAMPLE VIII The efficiency of the products of the process of this invention was also proved by testing selected substances in animals of larger size; the results being listed in the following Table VIII. The success was determined by repeated examination according to the McMaster process of the amount of worm eggs excreted and, in the case of selected examples, by dissection of treated and untreated dogs with comparison of the worm load present (controlled test). I-Iookworms are very important parasites in human and veterinary medicine from a hygienic anad also economic point of view. The efficiency of the derivatives of this invention, however, covers also other economically important helminthes in man and animal.

**Novilla, M.N. and RF. Flauta, Philipp. J. Vet. Med. 6, I35 144, I967. *usual treatment mode 7 As is shown in Tables VII and VIII, the superiority of the products of the process of the invention over comparative products is established (1) with respect to the excellent effect at subcutaneous and/or oral administration, and (2) with respect to the small dose necessary.

We claim:

1. A compound of the formula I 3. The compound as disclosed in claim 1 wherein the same is 4. The compound in claim 1 wherein the sameis N\ -continu.ed NH--COOCH;,

7. The compound as disclosed in claim 1 wherein the same is 5. The compound as disclosed in claim 1 wherein the same is NH COOCH /N O==CNH-SO2-NSOZ Cl. i \NHCOOCH3 0=c NH so, N so N0 6. The compound as disclosed in claim 1 wherein the The Compound as disclosed in Claim 1 whemin the same is same is 

1. A COMPOUND OF THE FORMULA 1
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 4. The compound as disclosed in claim 1 wherein the same is
 5. The compound as disclosed in claim 1 wherein the same is
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